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Results 301 - 350 of 587
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Thompson L H - - 1995
We have developed metabolically competent Chinese hamster ovary (CHO) cells to evaluate the genotoxicity associated with heterocyclic amines, such as those that are present in cooked foods. Into repair-deficient UV5 cells we introduced cDNAs for expressing cytochrome P450IA2 and acetyltransferases. We then genetically reverted these transformed lines to obtain matched ...
Kohlmeier L - - 1995
Dietary components express a wide range of activities that can affect carcinogenesis. Naturally occurring substances in foods have been shown in laboratory experiments to serve as dietary antimutagens, either as bioantimutagens or as desmutagens. Dietary desmutagens may function as chemical inactivaters, enzymatic inducers, scavengers, or antioxidants. Dietary components may also ...
Thiébaud H P - - 1995
Airborne cooking by-products from frying beef (hamburgers), pork (bacon strips) and soybean-based food (tempeh burgers) were collected, extracted, tested for mutagenicity and chemically analysed. The fumes generated by frying pork and beef were mutagenic, with 4900 and 1300 revertants/g of food cooked, respectively. No mutagenicity was detected in fumes from ...
Stavric B - - 1995
Food products derived from heat-treated (fried, broiled, baked) meat may contain traces of mutagenic heterocyclic amine contaminants, some of which are proven carcinogens in rodents. To confirm their presence and range in Canadian foods, and estimate the average human intake of these types of mutagens from frequently consumed heat-processed foods, ...
Hignett M - - 1995
OBJECTIVES: To study perforation rates of sterile transvaginal ultrasound probe covers before and after oocyte retrieval (OPU) in an IVF-ET program. METHODS: Transvaginal ultrasound probe sheaths from two different manufacturers were studied, Cook Innoray (Cook-Canada #TTUPS-100) and Swemed Lab (Frolunda Sweden #715). After controlled ovarian stimulation, OPU was done using ...
Lewis D F - - 1995
Quantitative structure-activity relationships between chemical structure and Ames mutagenicity for a group of 24 food mutagens, including 17 cooked-food heterocyclic amines, have been determined. For the TA98 strain of Salmonella typhimurium (frameshift mutagens) the best correlation of mutagenicity is with molecular diameter (R = 0.91), while for the TA100 strain ...
Knize M G - - 1995
Heterocyclic aromatic amines are sometimes formed during the cooking of muscle meats, and their mutagenic and carcinogenic effects are of potential concern in the aetiology of human cancer. In a large survey of the heterocyclic amine content of foods, fried or charbroiled hamburgers, fried chicken, chicken breast sandwiches, fish sandwiches ...
Duncan C - - 1995
High concentrations of nitrite present in saliva (derived from dietary nitrate) may, upon acidification, generate nitrogen oxides in the stomach in sufficient amounts to provide protection from swallowed pathogens. We now show that, in the rat, reduction of nitrate to nitrite is confined to a specialized area on the posterior ...
Lemke L E - - 1995
1-Hydrazinophthalazine [hydralazine (HDZ)] is a hydrazine derivative that is a direct acting vasodilator effective in the treatment of essential hypertension. HDZ is biotransformed by the phase II conjugation enzyme N-acetyltransferase (NAT) forming acetyl HDZ, which spontaneously cyclized to the stable product 3-methyl-s-triazolo- [3,4-alpha]-phthalazine (MTP). Therapeutic use of HDZ has resulted ...
Laquerbe A - - 1995
Using the 4,5',8-trimethylpsoralen in combination with the reirradiation protocol, we show that, in normal human lymphoblasts, the cytotoxic potential of photoinduced cross-links (CL) is higher than that of monoadducts (MA). In contrast to cytotoxicity, the significant increase in the proportion of CL, at a constant level of total adducts, had ...
Strickland P T - - 1995
The major sources of human exposure to environmental carcinogens are through inhalation, ingestion, and percutaneous absorption. Food-borne carcinogens constitute the primary source of ingested carcinogens. Epidemiological analyses indicate that 20-50% of all human cancer is due to dietary causes, unfortunately, few specific etiologic agents have been identified. The use of ...
Cabral L C - - 1995
Changes in cooking requirements and chemical composition of whole and dehulled soybeans, stored in 2 different environments [25 degrees C /75% R.H. (Environment 1) and 38 degrees C /90% R.H. (Environment 2)], were studied. Rate of water absorption and solid losses during cooking were higher for the dehulled soybeans at ...
Pobel D - - 1995
A case-control study on gastric cancer and diet was conducted in Marseille (France). Ninety-two patients with histologically confirmed adenocarcinoma and 128 controls undergoing functional reeducation for injuries or trauma were interviewed by a trained dietician using a dietary history questionnaire on their usual diet during the year preceding the first ...
Layton D W - - 1995
Heterocyclic amines (HAs) are formed as pyrolysis products during the cooking of meats/fish. These substances are potent mutagens in the Ames/Salmonella assay and are also carcinogens in laboratory animals. In order to assess the magnitude of the cancer risk posed by their presence in the US diet, we estimated the ...
Knize M G - - 1995
The mutagenic activity and the mass amount of heterocyclic amines responsible for the mutagenic activity have been measured in some cooked foods. Cooked meats are the predominant source of mutagenic activity in the diet with values ranging from 0 to 10,000 revertants per gram reported in the Ames/Salmonella test with ...
Gross G A - - 1995
Heterocyclic aromatic amines (HAs) may be formed during heat-processing of proteinaceous foods. All HAs are mutagenic in the Ames test, and many are animal and non-human primate carcinogens. The information on human dietary exposure is, therefore, of primary importance to accurately assess this health risk. A sensitive multiresidue method for ...
Ezeagu I E - - 1995
Nitrate and nitrite contents of seven varieties of commonly consumed leaf vegetables were determined. Effect of cooking and wilting on the contents of these factors were investigated. Nitrate ranged from 48.10 in ewuro to 270.0 ppm ogunmo (mean 116.43+/- 78.31) while nitrite ranged from 0.024 ppm in tete to 0.064 ...
Adamson R H - - 1995
Carcinogens occur naturally in the foods we eat, including a number of HCAs that have been identified in foods (beef, pork, poultry and fish) as a result of cooking. These compounds are formed during the normal cooking process by the reaction of creatine with various amino acids. The HCAs have ...
Grivas S - - 1995
A review of five different routes to the synthesis of the grilled or fried food carcinogen 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (8-MeIQx) and of closely related compounds developed in different laboratories is presented. Interest in the synthesis of these amines began in the late 1970s when the research group led by Professor T. Sugimura ...
Seel D J - - 1994
Gastric cancer is the commonest malignant neoplasm in Southwest Korea. The possibility of carcinogenic dietary factors led to the investigation of exposure to N-nitroso compound precursors among residents of the City of Chonju and of two outlying rural townships in North Cholla Province. Two traditional and widely consumed home-prepared food ...
Beijaars P R - - 1994
A collaborative study for the determination of nitrate in leafy vegetables, such as endive, lettuce, spinach, and beetroot, by continuous flow (CF) was conducted by the Project Group on Collaborative Studies of the Inspectorate for Health Protection, Food Inspection Service, in The Netherlands. After extraction with water and filtration, samples ...
Felton J S - - 1994
Mutagenic heterocyclic amines are generated in foods when they are cooked at temperatures over 150 degrees C. These compounds are present from 0.1 to 50 ppb, depending on the food and cooking conditions. These heterocyclic amines are not only present in cooked red meat, fish, and chicken, but are also ...
Stavric B - - 1994
Cooking of protein-rich foods may induce the formation of a series of heterocyclic aromatic amines (HAAs) that have been found to be mutagens and carcinogens. Despite very potent mutagenic activity found in the Salmonella/microsomal assay, this test cannot predict carcinogenic potency of HAAs in rodents and monkeys. Doses used in ...
Nardini B - - 1994
Twenty-seven extracts of airborne particulate from domestic environments, both in the absence of sources of pollution and during activities such as smoking tobacco, using a fireplace, and cooking using grills and barbecues, and eight control samples of outdoor particulate were tested using the Salmonella/microsome assay on strains TA98 and TA98NR. ...
Wang C J - - 1994
2-Acetylpyrrole (AP) is a product of model browning systems, and has been isolated as a major flavour component of many foods. Reaction of AP with nitrite produces two N-nitropyrrole compounds, 1-nitro-2-acetyl-pyrrole (NAP) and 1,3,5-trinitro-2-acetylpyrrole (TNAP), the chemical structures of which have been confirmed by spectral studies, including UV mass, nuclear ...
Gold L S - - 1994
Results in the Carcinogenic Potency Database (CPDB) on 11 mutagenic heterocyclic amines (HA) tested for carcinogenicity in rats, mice and cynomolgus monkeys are compared to results for other chemicals. An analysis of strength of evidence of carcinogenicity for HA vs. other mutagenic carcinogens and vs. all rodent carcinogens, indicates strong ...
Johansson M A - - 1994
Some typical Swedish meat and fish products, e.g. bacon, beefburgers, meatballs, Baltic herring, salmon, smoked fish, black pudding and sausages, and their corresponding pan residues, were analysed by HPLC for their content of mutagenic/carcinogenic heterocyclic amines (HAs). The products were cooked using recommended domestic cooking conditions concerning temperature, time and ...
Furr J R - - 1994
Activated Charcoal Cloth with silver (Actisorb Plus) and solutions of silver nitrate, but not Actisorb (Activated Charcoal Cloth without silver), demonstrated antibacterial activity against Gram-negative and Gram-positive bacteria. This activity was unimpaired in the presence of plasma. Sodium thioglycollate was an effective neutralizer of Actisorb Plus and of silver nitrate, ...
Straub B W - - 1994
The effect of food-related environmental factors on the formation of tyramine by Lactobacillus curvatus LTH 972 was investigated in liquid culture supplemented with tyrosine. The highest concentrations of tyramine (up to 201 mg/l) were formed at 30 degrees C, pH 5.2 and at a water activity (aw) of 0.97. At ...
Lee C K - - 1994
Cigarette-smoke condensate (CSC) is a complex mixture containing over 3800 identified chemicals including nicotine, water, mutagens, antimutagens, cytotoxins and inert chemicals. Although CSC is mutagenic in the Ames test, its effect on the activity of other mutagens has not been characterized. Using the Ames Salmonella bacterial mutagenesis assay, we found ...
Ji H - - 1994
The heterocyclic aromatic amines produced by high temperature cooking of foods containing creatin(in)e and amino acids (such as beef, pork, poultry and fish) are a class of potent animal carcinogens and have been implicated indirectly in human colon and pancreas carcinogenesis. We studied the urinary excretion of a mutagenic heterocyclic ...
Löfroth G - - 1994
The common food preparation processes, frying, broiling and baking, can give rise to air pollutants that are known to be mutagenic and carcinogenic in animal tests. A large number of persons can be exposed to such fumes as cooking is performed in most households and in many commercial enterprises. Additional ...
Bogen K T - - 1994
Quantitative estimates of potential cancer risk associated with eating heterocyclic amines (HAs) in cooked foods and food products, known to be highly mutagenic in the Ames/Salmonella assay and to cause cancer in laboratory animals, rely on estimates of carcinogenic potency from animal bioassay data. New estimates of potential human cancer ...
Ibe F I - - 1994
To investigate the possible presence of protein-bound mutagens in food an analytical procedure has been devised in which the sample is enzymically hydrolysed, fractionated by HPLC and examined by a modified liquid incubation Ames assay. To validate the method MeIQx was added, as a model compound, to beefburger and a ...
Dusdieker L B - - 1994
OBJECTIVE: To identify commercial baby food varieties high in nitrate content using ion chromatography and compare the health risk associated with the consumption of high-nitrate water and high-nitrate commercial baby food. DESIGN: Ion chromatographic determination of nitrate concentration in a variety of commercial baby foods. SETTING: University Hygienic Laboratory, University ...
Stavric B - - 1994
The role of dietary factors in the prevention of major chronic diseases, cancer in particular, is under intensive investigation by many laboratories around the world. Evidence from epidemiological studies and tests in laboratory animals suggests that food consumed by the general population contains certain ingredients that may have a role ...
Jin C J - - 1993
The capacity of four cDNA-expressed human liver UDP-glucuronosyltransferases (UGT), UGT1*6, UGT2B7, UGT2B10 and UGT2B11, to glucuronidate hydroxylated metabolites of benzo[a]pyrene (B[a]P) and 2-acetylaminofluorene (AAF) has been investigated. UGT1*6 and UGT2B7 glucuronidated a range of B[a]P and AAF metabolites with a degree of regiospecificity, although UGTs 2B10 and 2B11 were inactive ...
Ferguson L R - - 1993
One of the ways dietary fibers may protect against colorectal cancer is by adsorbing carcinogens and carrying them out of the digestive tract, thus lessening interaction of the carcinogens with the colonic tissue. We investigated this mechanism of action by testing in vitro the abilities of a range of carcinogens, ...
Eisenbrand G - - 1993
This review summarizes the abundant literature on food-borne heterocyclic amines, their chemistry and formation, their occurrence in food, their biological activities including mutagenicity, induction of DNA damage and carcinogenicity. Pharmacokinetics and biotransformation are also discussed. Factors that influence these effects are given consideration, with special emphasis on dietary factors that ...
Zeiger E - - 1993
Much attention has recently been brought to the fact that many natural components of the diet are mutagenic and/or carcinogenic. Approximately 2700 distinct chemical entities, chemical mixtures, and plant extracts are allowed as direct food additives by the US F.D.A. These include chemicals found in the body, natural components of ...
Gross G A - - 1993
The heterocyclic aromatic amines (HAAs) 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx) and 2-amino alpha carboline (A alpha C) were quantitated in grilled bacon and beef. The levels of PhIP in bacon ranged from < 0.1 to 52 p.p.b., MeIQx was detected at levels ranging from 0.9 to 18 p.p.b. Both ...
Atawodi S E - - 1993
Some common Nigerian foodstuffs were assessed for their content of preformed volatile nitrosamine by chemiluminescence detection following gas chromatographic separation. Nitrosodimethylamine levels of between 0.4 and 4.6 ppb were detected in 75% of the samples analysed. The highest value was found in Brassica oleraceae, while Vernonia amygdalina contained the lowest ...
Tikkanen L M - - 1993
The concentrations of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and DiMeIQx (i.e. the sum of 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline and 2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline) were determined as their 3,5-bis(trifluoromethyl)benzyl bromide derivatives in commercial heat-processed daily Finnish foods using the gas chromatography-mass spectrometry technique with negative chemical ionization. With this technique it was possible to detect picogram quantities of ...
Skog K - - 1993
Commonly eaten meat products prepared from beef, pork, mutton and chicken show some level of mutagenic activity following normal frying. Food preparation methods have a significant influence on the formation of the mutagenic activity. The main food mutagens found in cooked meat products are heterocyclic amines. Several of them have ...
Laitinen S - - 1993
Dietary intakes of nitrate and nitrite of 1212 Finns aged 9, 12, 15, 18, 21, and 24 years were calculated using food consumption data obtained by the 48-hour recall method in 1986, in connection with the Study on Cardiovascular Risk in Young Finns. Files on nitrate and nitrite content of ...
Steineck G - - 1993
In the fried meat surface layer (the meat crust) mutagenic heterocyclic amines are formed during cooking. A human cancer risk is conceivable after intake of such mutagenic activity. We investigated the current literature mentioning fried foods, and six studies of colorectal cancer, three of stomach cancer and one each of ...
Hislop T G - - 1993
Evidence that diet contributes to the development of cancer is strengthening. This paper examines mutagens and carcinogens, such as naturally occurring substances, products of cooking and food processing, intentional and unintentional additives, and contaminants, found in foods. Such substances are present in minute quantities in the diets of average Canadians. ...
Shephard S E - - 1993
Naturally occurring dipeptides, cholecystokinine (CCK, a tetrapeptide hormone) and the artificial sweetener aspartame were nitrosated for 10-30 min with 40 mM-nitrite (pH 3.5, 37 degrees C), and the resultant products examined for mutagenicity in Salmonella typhimurium TA100. Specific mutagenicities (net revertants per mumol precursor) spanned four orders of magnitude, with ...
Wakabayashi K - - 1993
Many mutagenic heterocyclic amines (HAs) have been isolated from cooked foods and pyrolysates of amino acids and proteins, and the carcinogenicity of 10 of these HAs in rodents and of 1 in monkeys has been reported. Quantification of these carcinogenic HAs in various kinds of cooked foods indicated that the ...
Boeing H - - 1993
A population-based case-control study was performed in South-West Germany in 1987/88 with 115 histological confirmed glioma and 81 meningioma cases and 418 randomly selected controls. On the basis of information from a food-frequency questionnaire and questions on food preparation and food supply, the role of dietary carcinogens, in particular N-nitroso ...
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